Machine for laminating elongated objects by wrapping

ABSTRACT

A MACHINE FOR LEVEL WINDING FILAMENTS ON AN ELONGATED FIXTURE WHICH REGULATES FILAMENT SPEED IN ACCORDANCE WITH THE REQUIREMENTS OF THE FIXTURE AND WHICH MAINTAINS CONSTANT TENSION ON THE FILAMENTS.

Jan. 19, 1971 R. J. DITLINGER MACHINE FOR LAMINATING ELONGATED OBJECTS BY WRAPPING Filed Feb. 5. 1968 2 Sheets-Sheet l Way/61. at;

ATTORNEY Jan. 19, 1971 R. J. D ITLINGER 3,556,995v

MACHINE FOR LAMINATING ELQNGATED OBJECTS BY WRAPPING 2 Sheets-Sheet 2 Filed Feb. 5. 1968 NS @Q W F w AT TOEN E Y mv aw United States Patent 8 Claims ABSTRACT OF THE DISCLOSURE A machine for level winding filaments on an elongated fixture which regulates filament speed in accordance with the requirements of the fixture and which maintains constant tension on the filaments.

SUMMARY This invention relates to improvements in manufacturing helicopter tie-bars, such as disclosed in US. Pat. No. 3,228,481 and laminated couplers, such as disclosed in US. Pat. No. 3,279,278 from a filament band such as the wire tapes disclosed in US. Pat. No. 3,189,510. It is also expected that the machine of this invention will be useful for the production of other filament wound products, especially those whose wrapping profile is other than a surface equidistant from the axes of rotation for the surface.

It has been observed that the prior art calling for the wrapping of elongated profiles to form a laminated object has not permitted automatic control of the filament band speed of delivery in relation to the changing speed requirements of the wrapping fixture, when other than a true circle is desired for the laminate. This has necessitated lengthy and precisely controlled manufacturing techniques. Furthermore, it has been deemed required in the prior art to manufacture bands of adhesively related filaments of the width required by the elongated profile width, and this has caused cumbersome grouping of filaments.

It is, therefore, the principal object of this invention to eliminate the aforementioned problems whereby small bands may be uniformly level wound into an elongated profile at a speed which will be matched to the cycloidic speed of the surface of the elongated profile as it is revolved to receive the bands.

It is a further object to utilize filaments on spools which are drawn around guides to orient them in a band.

It is also an object to regulate the tension of the filaments to a constant value regardless of distance of the point of their separation from the spools supplying same.

DRAWING DESCRIPTION DETAILED DESCRIPTION With regard now specifically to FIG. 1 there is shown a table formed by legs 10, 12 and 13 and side rail 14 plus end rail 16 to which a working platform or surface 18 is attached. The working surface 18 extends from one end of the table to the other end, and it may slightly extend beyond the ends of the table, end rails 16, as

ice

shown. To the extreme right end of this surface 18 a plurality of shafts 20 are threadedly affixed to the surface 18. To these shafts a wire tensioning mechanism 24 is revolvably aflixed carrying a plurality of filament spools 26. Filaments, such as the thread-like objects 28 and 30, which may be fine wires, are extended from the spools 26 about guide pulleys 32 and back towards a cleaning tank 34. These filaments pass through the cleaning tank 34 containing a cleaner whose composition is sufficient to remove any impurities on the surface of the filaments and emerge therefrom in a band 36 passing over a guide roller 38 then down to pass under a roller 40 emerging therefrom to pass over another roller 42 and project towards a resin pot 44. The roller 40 is operably connected to a cam follower 45 and revolvably secured between ears similar to ears 46 but on a lower end of a rod 48 reciprocably mounted within a cylinder 50 and positioned by springs '52 and 54 operatively connected to the lower end of the rod 48 as by a pin 56, which mounts roller 40, and to the exterior of the cylinder housing as by pin 58 to regulate the length of portion 60 of the band between the resin pot 44 and the roller 40.

The resin pot 44 has a sizing die 62 on its leftward face where a tape 194 emerges therefrom toward fixture 64 containing bushings 66 and 68 at opposite ends thereof about which the tape 36 is to be wrapped and joined to. The fixture 64 comprises inner and outer plates 70 and 72 which prescribe the width of the elongated profile surface between the bushings 66 and 68, which width is generally equivalent to the width between the flanges of the bushings. The inner plate 70 is attached to a shaft 74 which is provided on its end opposite that to which the fixture is mounted with gear sprockets 76 and 78. The shaft 74 is mounted to the work surface 18 by means of the bearing block 80 and 82, as by bolts 84. A roller 86 rides along the surface of the shaft 74 to operate a counter driving mechanism 88 for the counter 90 having a window 92 through which one can get an indication of a number of revolutions the fixture 64 has made whereby the number of layers of the adhesively integrated band 36 may be determined about the bushings 66 and 68. A chain 94 extends from a sprocket 96 on a shaft 98 that is connected by a chain 100 about sprockets 101 and 102 respectively connected to shaft 98 and a gear reduction mechanism 104. The gear reduction mechanism 104 is driven by a pulley 106 by a belt 108 from the electric motor 110. The shaft 98 is supported by bearing blocks 112 and 114 and mounts on its end opposite that to which the sprocket 96 is aflixed a cam 116 having a surface 118 that is calibrated as will be explained hereinafter, and which is operatively related to control the positioning of the cam "follower roller 40 for the plunger comprised of the rod 48 and cylinder 50 operatively related by springs 52 and 54.

The motor is fixed to the surface 18 by a mounting flange 120 and is connected by means of electrical conduit 122 to a control box 124 connected by an electrical lead 126 to an electrical source of energy via a wall receptacle 128 behind the table. The control box has a standard off-on switch 130 provided for energizing the communication of the electrical source of energy to the motor 110 and a rheostat control 132 for variably regulating the rpm. of the motor 110 in accordance with an r.p.m. indicator 134 on the face of the control box 124. Indicator lights 136 and 138 are also provided on the face of the control box 124 to respectively provide indication of the source of electrical energy and an overload condition.

The resin pot 44 is reciprocatorily mounted by means of a rod 140 slidably supported along the surface of the surface 18 of the table to vary the lateral attitude of the resin pot 44. A cam follower 142 is secured to the resin pot by means of nuts 144 on each side of a flange 146 extending upwardly from the resin pot 44. The cam follower 142 rides upon the surface 146 of a duo-lobe cam 148 that is driven by means of the gear reduction box 150 connected by sprocket 152 and chain 154 to sprocket 78 of the shaft 74 which is being driven by the motor 110. FIG. 2 shows a plan form of the machine which has a slightly different arrangement in that the belt drive is connected directly to shaft 74 by means of pulley 156 and the gear box 150' and the cam 116' is driven by a chain 158 between the shaft 74' and shaft 98 about sprockets 1-60 and 162 on the ends of these shafts. The gear box 150 is driven in the same manner as the gear box 150 of FIG. 1, i.e., by a chain 154 between sprockets 152' and 78'. a

FIG. 2 shows in clear detail how the several spools 26 are located on the work surface 18' such that the filaments, such as wires 162, 164, 166, 168, 170, 172, 174 and 176 are fed therefrom about the respective guide pulleys 178, 180, 182, 184, 186, 188, 190 and 192 to form the band 36 which is integrated by an adhesive in the resin pot 44' into the tape 194 that is wrapped in the channel 196 between the plates 70' and 72' of the fixture afiixed to the shaft74' to be rotated thereby, as by bolts 198. The channel 196, as can be clearly seen in FIG. 2, is of a width equal to the width of the body of the bushings between the respective flanges 66 and 68.

One other change in the machine shown by FIG. 2 is in the placement of a counter beneath the surface 18' that is directly linked to the driving of the pulley 156, as in a manner well known to those skilled in the art, to record the number of revolutions of the fixture and thereby indicate the number of layers of tape 194 wrapped about the bushings within the fixture.

With respect now to FIG. 3 there is shown the wire tensioning device 24 on the shaft that is contemplated for use with the machine of this invention. More particularly, this structure embodies a steel washer 200 that is press fitted to the shaft 20 and over which is placed a bronze washer 202 to be between a radial flange 204 of a spool carrying reel 206 having a pin 208 for uniting the filament spools 26 therewith. The frictional contact between the flange 204 and between the bronze annular disc 202 and the steel washer 200 is maintained by a spring 216 whose force is regulated by means of nut 212. The reel 206 is supported on the shaft for revolution by means of bearings 214 and 216.

OPERATION Initially the filament spools 26 are placed onto the reel 206 inserting the pin 208 in a hole in the bottom of the flange of the spools 26 (not shown). Thereafter ends of the filaments from the spools 26 are drawn therefrom around the respective guide pulleys 178, 180, 182, 184, 186, 188, 190 and 192 and passed through the cleaning tank 34 or 34' over the guide roller 38, under the cam follower roller over the guide roller 42 and through the resin pot 44 and/or 44'. After pulling the band of filaments through the resin pot 44 and/ or 44' the sizing die (see FIG. 1) 62 is placed within its slot in the face of the resin pot 44 and/or 44' from which the filaments emerge. The ends of the filaments are then partially wrapped around one of the bushings at either end of the fixtures 64 and/or 64' and clamped to the body of the bushing between the flanges. Thereafter the switch 130 is energized and the rheostat 132 adjusted to provide proper I.p.m. of the motor 110 whereby the fixtures 64 and 64 are now rotated by the motor 110 due to the chain and/ or pulley drive therewith. In wrapping the filament tape 194 onto the fixture, the lateral position of the tape is controlled by the die 62 in the resin pot 44 and 44, which is attached to plunger or shaft 140 so as to be free to move in a lateral direction. The position of the shaft and/ or plunger, with the attached resin pot, is controlled by the double lobe cam 148 the maximum and minimum radius of which is equal to the width of the channel 196 between the plates 70 and 72 or 70 and 72'. The gear box 150 is designed so as to revolve the cam such that it makes one-half revolution in the time it takes to level wind the wire of the channel 196 in the fixtures 64 and 64. During operation of the aforementioned machine, the lineal speed of the filaments in the band 36 and the tape speed 194 is continually changing due to the elongated shape of the fixture 64, 64'. A plot of this speed is a figure of cycloid. Because it is not. possible to rapidly accelerate and decelerate the heavy spools 26 of wire, these fluctuations in speed must be eliminated or else the machine is doomed to operate at a very low speed. At the same time the economics of manufacture dictate that a high wrapping speed be used. Thus a speed equalizer in the form of the cam 116 and roller type follower 40 is utilized to eliminate the fluctuation in the speed of delivery of the filaments, thus, permitting the spools 26 to turn at a constant angular rate. The cam 116 is a singlelobe cam which drives the plunger 48 in a reciprocating motion. In the embodiment shown, the speed of cam 116 is chosen so as to provide one equalizing cycle per revolution which is equal to one-half revolution of fixture 64. When the cam causes the plunger 48 to lengthen, the basic wire speed is increased, and vice versa when the plunger shortens. The instantaneous basic speed of the wires through the resin pots 44 and/ or 44 can be determined mathematically for any given fabricating fixture orientation. The differential speed that must come from the equalizer comprising the cam 116, follower 40 and plunger 48 within cylinder 50, and which must be impressed on the basic filament speed, is obtained by comparing the instantaneous filament speed to that of the average speed. With the differential speed, thus determined, the rate at which the plunger must be extending or contracting to produce the differential is computed. As the angular speed of cam 116 is known, it is then possible to arrive at the radii of adjacent points on the cam so that the proper velocity of the cam follower can be obtained. Therefore, this invention contemplates that by varying the speed of cam 116 and/or the profile of its surface 118, any irregular pattern can be wrapped at high speed while maintaining constant output speed for the filaments at the spools 26. Also by increasing the number of rollers 40 operable by cam 116, the movement of follower 45 may be reduced.

In closing this operation section, as will be readily apparent to those skilled in the art to which this invention relates in that it has been a critical requirement of all machines of this type up to this invention, the tension control of the filaments from the spools 26 is extremely critical. If there are substantial fluctuations in the tension between the supply spools, the finished laminated product will be defective. Thus, the tension for each of the spools in a machine of the type contemplated by this invention is controlled by individual compensating type tensioners for each spool. These tensioners take into account that the filament tension is proportional to the torque and inversely proportional to the outer radius of the filaments departure point on the spools 26 as explained above with regard to the description of a preferred embodiment of such a compensating type tensioner 24, a drag torque is created about the centerline ofthe spool and tensioner assembly which is developed by friction between the annular bronze disc 202 and steel washer 200 interface. It has been observed that these materials, the mean friction radius and the coefficient of friction are such that, as torque decreases due to a reduction in spool weight, the filament tension remains constant due to a reduction in the filament fill radius, i.e., the radius of the departure point of the filament from the spool. An added advantage of this tensioner 24 is that the spool 26 can be replaced without changing the tension settings.

The motor 110, in a preferred embodiment utilized thus farin fabricating products by this machine, is a onethird horsepower variable speed electric motor. This has been found to be the minimum power requirement. Larger constant speed motors can be used, depending on what fabricating fixture angular speed is desired.

Having fully described an operative construction as well as the operation and advantages of the invention, it is now desired to set forth the intended protection sought by these Letters Patents as follows.

I claim:

1. In a machine for fabricating elongated objects from a band of material of indeterminate length:

a platform;

an elongated mandrel mounted on said platform for rotation about an axis generally perpendicular to the longitudinal axis of the mandrel;

means on said platform to supply the material to be wound on said mandrel;

speed regulating means mounted on said platform between said mandrel and said supply means for regulating the speed of the band supplied to the mandrel; and

mechanism operatively connecting the mandrel and the speed regulating means for operating the latter as the mandrel rotates whereby the speed of the band between the supply means and the speed regulating means is maintained substantially constant and the speed of the band between the speed regulating means and the mandrel is varied in accordance with the position of the mandrel as the latter rotates.

2. The machine of claim 1:

said speed regulating means including a plunger reciprocably mounted on said platform;

one end of said plunger engaging said band for varying the amount of the material between the supply means and the mandrel as the plunger reciprocates;

said mechanism being connected to said plunger for reciprocating the latter as the mandrel rotates.

3. The machine of claim 2:

said mechanism including cam means engaging the other end of said plunger and drive means connecting the mandrel and the cam means for rotating the latter as the mandrel rotates.

4. The machine of claim 2:

said plunger being mounted for reciprocation in a substantially vertical plane;

said band moving in a substantially horizontal plane between the supply means and the plunger, then in a vertical plane around said one end of the plunger, and then in a horizontal plane between the plunger and the mandrel.

5. The machine of claim 1:

said supply means including spools of filament material rotatably mounted on said platform and means for arranging the filaments into said band as the filaments are pulled from said spools.

6. The machine of claim 5; and

a container of adhesive mounted on said platform;

said band passing through said container to coat the filaments with the adhesive before being placed on the mandrel.

7. The machine of claim 6:

said container being mounted on said platform between the mandrel and the speed regulating means and further being movable in a direction parallel to the axis of rotation of the spool to distribute material onto the latter.

8. The machine of claim 7:

said speed regulating means including a plunger reciprocably mounted on said platform;

one end of said plunger engaging said band for varying the amount of the material between the supply means and mandrel as the plunger reciprocates;

said mechanism including cam means engaging the other end of said plunger and drive means connecting the mandrel and the cam means for rotating the latter as the mandrel rotates.

References Cited UNITED STATES PATENTS 2,327,790 8/1943 Hopkins 2427.02X 2,984,286 5/1961 Copenhefer 156426 3,042,569 7/1962 Paul 156166 3,081,014 3/1963 Anderson et al. 24275.2X 3,083,887 4/1963 Huck 24275.3X 3,084,087 4/1963 Weil et a1. l5 6166 3,098,617 7/1963 Day 242206 2,481,314 9/1949 Knauf, Jr. 156425X FOREIGN PATENTS 144,791 4/ 1954 Sweden 154-1.6

BENJAMIN A. RORCHELT, Primary Examiner T. H. WEBB, Assistant Examiner US. Cl. X.R. 156166, 426 

